i dont think there way they went about it was the best choice but there motovation to keep the bird off earth at all cost is what is spot on!
Under that logic they should probably send the Lights to Pluto too, the phoenix might come for them. It did refer to them as its children. Also Rachel. Send her to Pluto too.
This is what amuses me: What do the Avengers know about the Phoenix? I understand that they are aware of it, but they've never faced it. These are the same Avengers who couldn't pull the trigger on eliminating Scarlet Witch after she murdered a handfull of their teammates. Now they think they're the best suited team to confront the Phoenix? Do the X-Men show up and tell them how to battle Kang the Conqueror? It must be a slow day at the Avenger's Mansion for them to bother to get involved.